Automatic telephone system



Oct. 2, 1928.

B. D. WILLlS AUTOMATIC TELEPHONE SYSTEM Original Filed May 1922 Z Sham-Sheet Bernard Dlflfilhs Oct, 2, 1928. 1,686,306

B. D. WILLIS AUTOMATIC TELEPHONE SYSTEM Original Filed y 25. 1922 2 Sheets-Sheet 2 Inuen m:

' Barnard D -Mflhs Patented on. 2, 1928.

units stares tease-t BERNARD nwrLLIs, OF AK PARK, ILLINOIS, ASSIGNOR, BY mm Aeneas-Ems,

T0 AUTOMATICELECTBIC Inc, OF CHICAGO, ILnmoIs, A CORPORATION OF DELA- WARE.

AUTOMATIC Ter inate 's'Ys'TEm;

Application filed May 25, 1522, Serial m ma Renewed December is, 192a The presentinvention relates in general proceed to inform the calling party tha'tth e called station is no longer accessible, or that it is accessible under anew number. With an arrangement of this kind it is essential when a call set up by a calling subscriber is intercepted by an operator due to the called line having been disconnected, that no charge I be made to the calling subscriber for the call.

It is also essential it the call set up has originated at atoll operators position, that supervision be given to the toll Operator regardless ot' whether theca ll is extended to a working subscribefls line, or to an intercepting Operator.

The principal object of'this invention is the provision of an improved, simple, and inexpensive operators cord circuit to be used in connection with a so called traffic or intercepting trunk, for answering calls orig'i nating' either at a subscribers station orat a toll operators posit-ion, and for extending such calls to any desired line it the Occasion requires. i

Figs.- 1 and 2 illustrate a preferred in stallation. v

Referring); to Fig. 1 of the drawings, in the upper ortionthere is shown a co'rdcircuit 0 having access through the usual plug P, jack J, toll selector E, toll transmission repeater D, second selector F, and the combination toll and regular connector H, to cal-led lines", such as A, and to answering jacks such as J, Fig. 2, in cases Where the called line, such as A, has been disconnected.

In the lower portion of Fig. l is indicated a local substation" A'having accessthrough the usual lin'e switch C, first selector E, second selector F, and connector H to called lines such as Aflthe'connector H having at cess to the same group of called lines'as the connector H; i p

In Fig. 2 is illustrated a cordcircuit O which is used by the intercepting operator for answering calls which have been eXtended to jacks such as the jack J,"an;d for extend ing such calls to a desired subscribers line over jack J 2 and line switch G I The circuit arrangements shown per portion of Fig. 1, with the exception of the line switch C. and the substation A, are" fragmentary portions of certain of the drawings shown in the Nicks Patent, No. 1 ,616,

of a transmitter 5, receiver 6, ringer Land a v calling device S. Theline' sw itchc may be ofthe usual. type, which maybe briefly described as a rotary line switch whose wipers have no normal position, and which have movement in a forwarddirection only. I The operation of switches of this character are well known and need not be further as: scribed;

The first selector and the connector H are of the same me-. chanical structure as the switches E, F an H, that is, they are of the strowg'er vertical and rotary type,but are wired for operation in accordance with the two wiresystem'of ontr01=,-ana in view of the fact that ,the circuits for operating switches or this character to extend tloctl lconnections are well ltno'wn it is thought that their dperation will be clearly understood.

a, an sconasasaar i 4 in the up;

v or toll apparatus operated by a reversal of the calling line circuit may. be used however. The cord circuit Fig. 2, issimilar to the usual type, but has been modified to operate and function so as to properly carry out the object of the invention, as will be described hereinafter. i

on the drawingmarked Fig." 1,"the relays which have slow acting characteristics are denoted bythe shading on the lower ends of their cores or else bythe solid black portion on the upper ends of their cores. The relays which have cores shaded on the lower end are the usual so-called slow acting relays and are slow to fall back but not noticeably slow to pull up. On the other hand, the relays which have their upper ends of their cores shown solid black are slightly slow to pull up in addition to being slow to fall back.

The general object and scope of the invention having been pointed out, and theapparatus IIIVOlVGCl having been described, the

operation will now be set forth more in detail by explaining the setting up of connections from the cord circuit 0 and the substation A to the operators position at which calls are answered by use of the cord circuit O. I

It will first be assumed that the toll oper ator, or the operator having the cord circuit 0, desires connection with a certain substa: tion to whichthe connector H has access, but

which has had the service disconnected for nected fromthe line, as stated.hereinbefore,

and will be connected by temporary jumpers such as 307 and 276 to a traffic trunk. The

operator proceeds by inserting the plug P into the jack J extending to an idle selector E, and throws the key K to associate the call-v ing device S with thelinc relay 51 of the selector E. i

The operator now proceeds to operate the calling device S in accordance with the various digits of the desired called number, thereby successively controlling the line relays 51, 151, and 201, to control their respective switches E,F;. and H, to complete the connection in the well known manner.

Upon completing the impulse sending op'er ation, the operator will momentarily actuate the ringing key K so as to unlock the ring out off relay 205, which was locked up when the connector H was given its first vertical im pulse. The initial energizing circuit of relay 205 includes contacts 219, which are closed during the vertical movement of the connector; and the locking circuit includes contacts 236, which are closed while the connector; is inuse, except when opened by suitable relay means responsive to the actuation of the open ators ringing key, as above mentioned. These circuit arrangements are fully described in the Wicks application Patent No. 1,616,402, previously referred to. Relay 205, upon restoring, completes a ringing circuit for operating the. ring down relay 301 in the traific trunk, which may be traced asfollows: Interrupted generator Gen, resting contact of armature 229 and said armature,wiper 272, bank contact 275, jumper'276, conductor 277,

upper winding of the ring down relay 301,

upper armature and resting contact of relay 300, conductor 306, jumper 307, bank contact ofarmaturell'? and said armature, lower left hand winding of the repeating coil R, bank contact 7 7, and wiper 73 back over the ring side of the cord'circuitO, winding of relay 3, tip side of cord circuit 0, wiper 70, bank contact 74;, upper left hand winding of the repeating coil R, armature 116 and its resting contact, and resistance 112 to battery.

Current flow over-this circuit results in the operation of the supervisory relay 3, which causes the lamp L to light.

The operator at the cord circuit 0, upon seeing thecalling lampL lighted, answers by inserting the plugP into. the jack J, which completes a circuit from. battery, winding of relay 3.00, sleeve of ack J, sleeve strand of plug P, and-"resistance X to ground. Relay 300, upon energizing, opens at its upper and lower armatures and back contacts both windings of relay 301., Relay 301 therefore deenergizes and extinguishes the calling lamp L. At the same time, a circuit is completed for the ringcut as relay 205 which may be traced as vfollows: from ground, resting contact of armature 311 and said armature, winding of impedance coil 310, tip of plug P, tip spring of jack J, conductor 306, jumper 307, bank contact 273, wiper 270, armature 277 and its resting contact, and the upper winding of ring cut off relay 205 tobattery. The operation of relay 205 disconnects the generator at its armature 229, and at the same armature and armature 277 extends the trunkline directly to the jack J. In. addition, at its armature 228 relay 205 closes alocking circuit for itself to the release trunk, in a well known manner. As a further result of the energization of relay 205,; a circuit is completed for the battery feed relay 100, which is substituted for the upper Winding of relay 205 in the circuit above traced extending over the tip side of the traffic trunk and through impedance coil 310 at cord circuit 0 to ground.

aceaeee Belay 100 is accordingly energized and: at its armatures- I16 and 117' disconnects battery and ground from the conductorsleading back to the-supervisory relay 3 of the cord circuit 0'. Relay 3 deenergizes and extinguishesthe lamp L, thus giving the toll operator answering supervision. I

The toll operator may now throw her key K to listening position and on finding that the answering party is an intercepting operator she will give such operator the number of the called party and will in turn be ad'- vised by the intercepting operator as to the condition of his'li-ne. If the desired subscriber has been permanently disconnected,

operator has not withdrawn the plug P, a

circuit will again be completed for the relay 3 in the cord circuit 0, this time causing the lamp L to ligh-t,.to indicate to the toll operator that a disconnection is desired, whereupon she will withdraw the plug P and cause the various switches to be restored in the usual maner.

It will now be assumed that the connection has been set up from the substation A. In

this case the various switches C, E, F", and 1-1 will have been operated in the usual manner to. extend the connection to the jack J. The ringing operation, although automatically. initiated, will be similar to that previously described. lVhen the intercepting operator inserts the plug P into the jack J", a circuit is completed through the impedance coil 3.10 and the ring cut oil relay 205. After the operation of relay 205", a circuit is completed from ground, winding of impedance coil 310, tip of plug P, tip strand of jack J, conductor 306, jumper 307, bank contact 273, wiper 2.70, armature 277" and its working contact, and the upper winding of back bridge relay 200 to battery. At the same time another circuit is completed from ground, lower winding of back bridge relay 200, armature 229and its working contact, wiper 272, bank contact 275, ring spring of jack J, ring of plug P, winding ofiinpedance coil. 312, armature 305 and its rest"- ing contact, to. positive battery and ground. Owing to the fact that the current now flows in opposite directions. in the twowindings of back bridge IBltLfYnQOO, a. di'fierential efl'ect is'produc-ed, and the relay will not energize. No reversal of'current flow in the calling line circuit will take. place, therefore, and consequently the polarized meter magnet 24 associated with the first selector-'1 will. not be operated;

The intercepting operator operates her listening key K" as. before, and procccd'sto inform the calling subscriber of the disconnection or change in. number of the; desired party. If the desired party has been disconnected from service, the calling subscriber replaces the receiver, causing the switching apparatus to be restored in the usual manner. 1 c

It may be, however, that the called sub:- scribers telephone number has merely been changed. Under these circumstances, the intercepting operator will inform the calling subscriber of the new number, after which the subscriber may momentarily hang up his I receiver and then proceed to setup the connection in accordance with the new number, or the operator may completethe connection for the subscriber. Under the latter condition the operator inserts the calling plug? into an idle jack, such as J connecting the polarized relay 308 in bridge of" the trunk.

This completes an operating circuit. for the line switch G which operates to hunt for and seize an idle trunk line. When the plug P is inserted in thejack J a circuit isralso completed for the relay 313. Belay 313 operates to complete a circuit for the supervisory signal L The operator then throws the calling device key K to substitute the calling device S for the polarized relay 308.

The operator now proceeds to set up the connection in the usual manner, and afterdialling the complete called number restores the key K. to normal, thereby again inserting ground and positive battery from the previously described back bridge relay 200 in the connector H", and at the front contacts of these armatu'res completes a -direct bridge 1 across the tip and ring strands of the cord. The relay 200 now operates, causing the current flow in the calling line to be reversed, resulting in the operation of the meter control relay 24. Although shown as a simple polarized relay, in actual practice relay 24x would be an electro-polarized relay of the type shown in the Ray patent, previously referred to. The operation of the relay 24c completes the operating circuit of meter magnet MM to charge for the call, in the same manner as if the call had been directly set up by the calling subscriber. When the conversation is com-- pleted the called subscriber. upon replacing his receiver causes the polarized relay 308 to deenergize, again completing the circuit for the lamp L and thus notifying the intercept ing operator that a disconnection is desired.

Should the call have originated at an iiiformation operators .position, the intercepting operator would have set up the connection in the same manner as has been explained for a subscriber. In this case instead of operating a meter, the information operators and the intercepting operators supervisory lamps would be extinguished when the called subscriber answered, these lamps again lighting when a disconnection was desired.

What is claimed is:

1. In a telephone system, a traflic trunk, two trains of switches by means of which calls may be extended to said trunk, a battery feed relay bridged across the talking conductors at one of the switches in each train, an operators link circuit adapted to be connected with said trunk to answer calls received thereover, and circuit connections in said link circuit adapted to cause the energization of the associated battery feed relay in case a call is answered which has been extended over one of said switch trains, but adapted to prevent the energization of the associated battery feed relay in case a call is answered which has been extended over the other switch train.

2. A system according to claim 1, in which one of the battery feed relays is single wound and the other double wound, and in which the double wound relay is prevented from operating by the differential eliect of currents flowing through its two windings in opposite directions. I

3. A system according to claim 1, in which one of the battery feed relays is single wound and the other double wound, in which the double wound relay is prevented from oper ating by the differential effect of the currents flowing through its two windings in opposite directions, and in which the link' circuit includes a battery of opposite polarity to the main exchange battery for causing the differential action at the double wound battery feed relay.

4. In a telephone system, a temporarily established connection including a subscriber controlled connector switch, a trunk line, and an operators .cord circuit, a double wound back bridge relay connected across the talking conductors at said connector in series with a battery, a circuit for one winding of said relay including the said battery, a conductor of said trunk line, and one strand of said cord circuit, and a second circuit for preventing the energization of said relay, said second circuit including another conductor of said trunk line, another strand of said cord circuit,

and a battery associated with the cord circuit of opposite polarity to said first battery.

5. In a telephone system, a temporarily established connection including a subscriber controlled connector switch, a trunk line, and an operators cord circuit, a double wound back bridge relay connected'across the talking conductors at said connector in series with a battery, a circuit for one winding of said relay including the said battery, a conductor of said trunk line, and one strand of said cord circuit, a second circuit for preventing the energization of said relay, said second circuit including another conductor otsaid trunk line, anotherstrand of said cord circuit, and a battery associated. with the cord circuit of opposite polarity to said first battery, means for extending the connection to a called line, a relay in said cord circuit controlled by the called subscriber, and contacts controlled by said relay for clearing both strands of the cord circuit of their normal battery connections and for closing abridge across said strands to energize the said back bridge relay.

6. In a telephone system, a subscribers line, an operators position, a .trunk terminating at said position, a first and a second automatic switch having access to said line and said trunk for extending calls either to said line, or said operators position via said trunk, answering responsive means in each of said switches operative when a call is extended to said subseribers line and is anis answered by the operator and for preventing the operation of the answering responsive means in said second switch when a call extended to said operators position via said second switch is answered by the operator.

7. In a telephone system, a subscribers line, an operators position, a trunk terminating at said position, a first and a second automatic switch having access to said line and said trunk for extending calls either to said line, or said operators position via said trunk, answering responsive means in each of said switches operative when a call is extended to said subscribers line and is answered by the called subscriber, a cord circuit at said operators position for answering calls extended thereto, means in said cord circuit for operating the answering responsive means in said first switch when a call extended to said operators position via said first switch is answered by the operatorand for preventing the ageeeisoe for operating said answering responsive means in said second switch.

8. Ina telephone system, a connector, an operators position, a subscribers line and a trunk terminating at said position accessible to said connector, means for operating said connector to extend a connection to said line or to said trunk, means at said position for extending a connection from said trunk to said line, and answering responsive means in said connector operable when the subscriber on said line answers the call irrespective of whether the call has been extended to said line from said connector directly or from said connector via said operators position.

9. In a telephone system, a connector, an operators position, a subscribers line and a trunk terminating at said position accessible to said connector, means for operating said connector to extend a call to said line or to said trunk, answering responsive means in said connector operable when a call extended to said line via said connector is answered by the called subscriber, a cord circuit at said operators position for answering calls extended thereto, means in said cord circuit for prevent ing the operation of the answering responsive means in said connector when a. call extended to said position via said connector is answered by the operator, means including said cord circuit for extending a call from said position to said line, and means in said cord circuit for operating said answering responsive means in said connector when a call extended to said line via said connector and said cord circuit is answered by the called subscriber.

10. In a telephone system, a calling line, a. meter, a called line, an operators position, means for extending a call from said calling line to said called line or to said position, means for operating said meter when a call extended from said calling line to said called line is answered by the called subscriber, means for preventing the operation of said meter when a call extended to said position is answered by the operator, means at said position for extending a call extended thereto to said called line, and means for operating said meter when a call extended from said calling line to said called line via said positionis answered by the called subscriber.

11. In a telephone system, a calling line, a meter, a called line, an operators position, means for extending a call from said calling line to said called line either exclusive of any operators position or via said position, and means for operating said meter when a call extended from said calling line to said called line over either route is answered by the called subscriber.

12. In a telephone system, an operators cord circuit comprising two sections, a bridge including a battery normally across one section of said cord circuit, a called line, means for extending a conn ection to said line via said cord circuit, and a polarized relay bridged across the other section independent of said batteryjand operative when the called subscriber answers the call for excludingsaid subscriber answers the call for excluding said battery from said bridge.

14. In a telephone system, an operators cord circuit comprising two sections, a bridge including a battery normally across one section of said cord circuit, a called line, means for extending a connection to said line via said cord circuit, said connection including an automatic switch between the cord circuit and the called line, and a relay bridged across the other section of said cord circuit and operative when the called subscriber answers the call for disconnectin said normal bridge and connecting anotherbridge across said one section excluding said battery.

15. In a telephone system, a connector, an operators position, a subscribers line and a trunk terminating atsaid posit-ion accessible to said connector, means for operating said connector to extend a connection to said line or to said trunk, means at said position for extending a connection from said trunk to said line, and a meter responsive when the subscriber on said line answers the call irrespective of whether the call has been extended to said line from said connector directly or from said connector via said operators position.

16. In a telephone system, a calling line, an operators position, a directively controlled automatic switch common to said calling line and other lines, means including said automatic switch for extending a connection from said calling line to said operators position, a called line, means at said operators position for further extending the connection to said called line, means responsive when the call is answered by the called subscriber, and a meter responsive to the operation of said last means.

17. In a telephone system, a calling line, an automatic switch common to said line and other lines, an operators cord circuit, a called line, means for extending a connection from said calling line to said called line via said switch and said cord circuit, means in said switch responsive when the called subscriber on the called line answers the call, and a meter individual to said line and responsive to the operation of said last means,

18. In a telephone system in which connections to called lines areestablished by way of an automatic switch having a double to an operators position is answered by the wound back-bridge relay which is operated operator for establishing a flow of current when a call is answered by the establishment in the two windings in opposite directiOns to 10 of a flow of current in the two windings in prevent the operation of said relay.

5 the same direction, and in which calls to dis- In witness whereof, I hereunto subscribe abled lines are trunked to an operators pomy name this 19th day of May, A. D. 1922. sition, means responsive when a call trunked BERNARD D. WILLIS. 

